Method and ststem for denying soaring and migratory birds access to critical areas of airports and aircrafts

ABSTRACT

A method is provided for mitigation of aircraft bird strikes through the provision of conditions on the ground that totally prevents the formation of atmospheric thermals in the proximity of airports and airfields, whereby conflicts between soaring and migratory birds and aircrafts may be avoided. This is accomplished by modification of the topography of the field into a plurality of zones, as described herein and through construction of high albedo pavements, roads, artificial turfs and cool terrains.

This invention was made with government support under Contract Number:FA9302-10-M-0011 awarded by The United States of America as representedby the Department of the Interior, Washington, DC. The government hascertain rights in the invention.

TECHNICAL FIELD

The invention relates to a method for denying soaring and migratorybirds access to critical areas of airports and aircrafts and paths oftaking off and landing aircrafts. More particularly, the inventionsprovides a method of eliminating a potential formation of thermals orup-draughts essential for lifting soaring and migratory birds, therebyavoiding conflicts between taking off and landing aircrafts and soaringor migratory birds.

BACKGROUND

Bird strikes happen most often during takeoff or landing, or during lowaltitude flight of aircrafts. The majority of bird collisions occur nearor on airports (90%, according to the International Civil AviationOrganization (ICAO)) during takeoff, landing and associated phases.According to the FAA Wildlife Hazard Management Manual (2005), less than8% of strikes occur above 900 m (2,953 ft) and 61% occur at less than 30m (100 ft). The point of impact is usually any forward-facing edge ofthe vehicle such as a wing leading edge, nose cone, jet engine cowlingor engine inlet. For example, turkey vultures and red-tailed hawksaccount for the majority and more costly of damaging raptor strikes toUSAF aircrafts, which amount to 31% and 32%, respectively. As of Jan. 1,2008, turkey vultures were responsible for 798 bird strikes costingabout 52 million dollars while the red-tailed hawks were responsible for814 strikes with about 14.6 million dollars in damages. Both turkeyvultures and red-tailed hawks showed a marked increase in the number ofbird strikes during the summer. This was due to the relationship betweenthermal activity and strike rate for these two species. Both forage bysoaring on thermals, without which they are unlikely to reach the heightrequired to bring them into conflict with aircraft. Thermals are formedon dark earth, black tops, roadways, towns, urban areas plowed fieldsand exhaust gas from power plants in the presence of cumulus clouds. Onthe other hand, sun reflective surfaces, marshes, and white coatedsurfaces do not support thermals. The most pronounced damage was causedby the American white pelican reaching about 257.65 million dollars inspite of their low number of strikes. Other thermal soaring birdsresponsible for the top 50 USAF wildlife strikes include buzzards,eagles, kites, gulls, herons, pelicans and terns.

The typical lift-off speed for an F-15 fighter plane is 150 knots. ABoeing 747, for example, spends longer time in critical path. Theaircraft acceleration during takeoff and landing hinders any birds'reaction to avoid collision. Reaction time of birds relative to themotion of the aircrafts is very important for survival of the birds andthe avoidance of damage to the aircraft. Such reaction time for soaringbirds will be much longer compared to free flying birds.

Accordingly, there is a need to eliminate soaring and migratory birds'conflicts with aircrafts. There is also a need to eliminate theformation of atmospheric thermal currents or thermals in the immediatevicinity of the airports and airfields proper and along the paths oftaking off and landing of aircrafts. In addition, there is a need toprovide high albedo surfaces in the airport including surfaces of thebuildings, runways, roads and the surrounding terrain while preservingthe aesthetics of the surfaces. Furthermore, there is a need toconserve/protect migratory birds and soaring birds by providing themwith sanctuaries and/or habitat away from airways.

SUMMARY

The invention provides a method for creating a thermals-free zone thatmay include the expanse of airports and airfields proper and at the sametime denying soaring and migratory birds' access to such zone.

According to one embodiment consistent with the claimed invention, amethod is provided for denying soaring and migratory birds access tocritical areas of airports and airfields and paths of taking off andlanding aircrafts, comprising eliminating a potential formation ofthermals or up-draughts essential for lifting soaring and migratorybirds and dividing the critical areas of airports and airfields andpaths of taking off and landing aircrafts into a plurality of zones.

In one aspect of the invention, the plurality of zones include anairport zone 1 or a thermals-free zone 1 that includes an airside areaand a landside area of the airports and airfields and the paths oftaking off and landing aircrafts; an unrestricted zone 3 of open andpublic spaces that are not under the control of operators of theairports and airfields; an exclusion zone 2 that separates thethermals-free zone 1 from the unrestricted zone 3; a green area zone 4that provides protection, sanctuary and abundant food and water supplyfor the soaring and migratory birds; a bird sanctuary zone 5 forconservation and creation of a habitat for the soaring and migratorybirds; and a water body zone 6 that is immune to the potential formationof thermals surrounding the thermals-free zone 1 from the unrestrictedzone 3.

Still other aspects, features, and advantages of the present inventionare readily apparent from the following detailed description, byillustrating a number of exemplary embodiments and implementations,including the best mode contemplated for carrying out the presentinvention. The present invention is also capable of other and differentembodiments, and its several details can be modified in variousrespects, all without departing from the spirit and scope of the presentinvention. Accordingly, the drawings and descriptions are to be regardedas illustrative in nature, and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of an overall layout of a sample airport thatinclude an airport zone 1 or a thermals-free zone 1, an exclusion zone 2and an unrestricted zone 3 (not drawn to scale);

FIG. 2 shows a cross-section of the ground of the airside and landsideareas of thermals-free zone 1, buildings, exclusion zone 2 andunrestricted zone 3 of the sample airport shown in FIG. 1;

FIG. 3 illustrates the use of a gravel easement 114 on each side of thepavement of the airside and landside of thermals-free zone 1;

FIG. 4 illustrates the active cooling of each of the gravel easements114 as depicted in FIG. 3;

FIG. 5 illustrates the active cooling of the pavement of the airside ofthe thermals-free zone 1 using a plurality of water pipes 162;

FIG. 6 illustrates the construction of a bird sanctuary zone 5; and

FIG. 7 illustrates the construction of a green zone 4 for soaring andmigratory birds.

DETAILED DESCRIPTION

The degree of solar heating of the ground depends on many factors, e.g.solar insolation in the area; color, mass and condition of the exposedsurface; specific heat and thermal conductivity of the substance of theexposed surface, and location of the substance on the surface of theearth in relation to other nearby objects.

Surface color, as known in the law of physics, plays a very importantrole in the phenomena of radiant heat absorption and emission.Therefore, a white body surface can, under similar conditions, emit alesser amount of sensible heat than a black body per unit surface.

In consistent with the features of the invention, it is desirable tohave a cold body surface surrounded by a warmer body surface to mitigatethe conditions that lead to the formation of thermal currents. By doingso, it allows for an exclusion distance (exclusion zone 2) that wouldavoid stray birds and, at the same time, accommodate planes thatovershoot their planned flight path. Under these conditions, cool airfrom the cold area will not only continually flow over the hot area butwill also be raised in temperature, expand, decrease in specificgravity, and eventually rise up. Based on the above, it becomes possibleto provide migratory bird species and other birds with a non-restrictedprotected area (unrestricted zone 3) or a sanctuary (bird sanctuary zone5) at a distance far enough from flight paths so that they can roost,nest, feed and forge freely while avoiding conflicts with arriving anddeparting aircrafts.

In the airport proper (thermals-free zone 1), the whole airside areas(including all areas accessible to aircrafts, e.g., runways, taxiways,ramps and tank farms) may be kept at a temperature close to that of theair temperature of a cold body or white body using passive means, e.g.,high-albedo surface-coating and/or reflective materials. In areas wherein the summer heat is excessive and characterized by higher insolationover extended periods, active means may be used, e.g., application ofcooling water. Exposed surfaces of terminal buildings, hangers, cargostorages, service buildings and tank farms, etc., may be coated withwhite coating and/or reflective materials. Landside areas includingparking lots, public transportation train stations (if any), and accessroads may have at least off-white colors on their surfaces.

U.S. Pat. No. 7,198,427 to Carr et al. discloses a safety system forairports and airfields that includes (1) an aesthetically pleasingartificial turf that retards birds and other animals and (2) asub-surface that supports the weight of an aircraft, enhances waterdrainage and enables the accessibility of airport vehicles to all partsof runway or taxiway, and methods for installing the safety system.However, the green color of the artificial turf according to Carr et al.supports thermal formations that attract gatherings of soaring birdshaving a free-lift to collide with planes at relatively low altitude.

In fact, work by others promoted the formation of artificial thermals infavor of facilitating the flights of sailplanes and gliders. Forexample, in U.S. Pat. No. 2,268,320, Brandt describes the production ofatmospheric or thermal air currents in the immediate vicinity of theairport by heating large volumes of air either by solar or artificialmeans to provide up-draughts that are essential to soaring or glidingflights. In addition, U.S. Pat. No. 2,371,629 to Lee discloses a meansfor forming an artificial thermal or ascending warm air current forsail-plane soaring that can be actuated by solar radiation.

The method, in consistent with the features of the claimed invention,may provide an extension of the thermals-free zone 1 around the expanseof airports and airfields, which, in turn, allows ample distances foraircraft flight paths during aircraft take-offs and landings, withoutcreating conflicts between any size aircrafts and soaring and migratorybirds. It may also secure the thermals-free zone 1, particularly on theairsides of airports or airfields by active cooling the surfaces of thepavements of the airsides. It may also provide an exclusion area 2 ofsufficient width around the thermals-free zone 1 for separating the zonefrom birds' habitats, sanctuaries and roosting areas, thereby preventingpossible collision between stray soaring birds and aircrafts that divertfrom their flight paths. It may further provide a safe protected areafor birds to roost, nest, feed and soar freely away from air traffic.

Hereinafter, the invention will be described more specifically by way ofexamples. It is to be noted, however, the invention is by no meanslimited to these examples.

EXAMPLES

As described in FIG. 1, there are a plurality of zones that can becontemplated in accordance with the features of the claimed invention.The plurality of zones include an airport area 1 or a thermals-free zone1, an unrestricted zone 3, an exclusion zone 2 that separatesthermals-free zone 1 from unrestricted zone 3; a green zone 4 that islocated on the unrestricted zone 3 and includes grass, shrubs, trees,etc.; a bird sanctuary zone 5 that serves as a protected area for birdsto nest, rest, roost and soar; a water body zone 6 such as a lake,man-made pond or alike along the runway may protect the aircrafts duringtakeoff from collisions with soaring birds at a relatively higheraltitude. Although the sketch in FIG. 1 applies to one runway in a smallairport, the principle may be applied to multi-runway airports.

As shown in FIG. 2, the exposed surfaces and sidings 112 of the controltower, terminal buildings 11, tarmacs 13, cargo 14, hangars and otherstructures, such as service buildings, may be made of reflectivematerials. The roofs 111 may be coated with special coating material,such as a mixture of various silica and ceramic beads immersed in a highquality latex base with acrylic binders; e.g., Temp-Coat® (manufacturedby SPAN-WORLD Distribution, LLC) and Thermal-Coat™ (manufactured byInnovative Coating Solution, Inc.) and the like or better.

As illustrated in FIG. 2, the creation of cold or white body requiresthe use of high-albedo pavements constructed from white cement concrete161. Accordingly, the airside areas of the airport area 1 orthermals-free zone 1, including taxiways 16, runways 17, tarmacs 13 andthe ground around tank farms 15 may be paved with white cement concrete161 directly over the earth surface 7 and may be surfaced with a whitecoating, e.g., white cement coating.

Also described in FIG. 2, the landside areas of the airport area 1 orthermals-free zone 1, including terminal 11, parking lots 12, cargo 14,public transportation train stations (if any), and access roads may bepaved with an asphalt layer 101 with an upper layer 102 made oflight-colored, non-heat absorptive material that acts as a thermalinsulator. The material of upper layer 102 needs to be water-insolubleso that it will remain intact during wet seasons. Examples of thematerial for upper layer 102 may include aggregates (e.g., granite,limestone or water insoluble salts, such as chalk, crystallized gypsum,magnesium oxide, etc.). Additionally, the pavement may be surfaced witha top-coat 103 made up of mixed chippings of sand and oyster shells,etc., as shown in FIG. 2.

An artificial turf may also be constructed in the exclusion zone 2, inaccordance with the disclosure of U.S. Pat. No. 7,198,427 to Carr etal., with the selection of a lighter color artificial turf instead. Thisis due to the ability of the artificial turf to discourage birds'presence. However, it is well-known fact that plowed fields and wellgroomed grass are good source of thermals. Accordingly, one embodimentof the invention, as shown in FIG. 2, is the use of an off-white colorfor top layer 201 in the exclusion zone 2. The top layer 201 is over theasphalt 101 and may be constructed from gravel mixed chippings of sandand oyster shells.

In FIG. 3, the white concrete pavement 161 of the airside of the airportarea 1 or thermals-free zone 1, may have a first and a second graveleasements 114 on each side of the white concrete pavement 161. Each ofthe gravel easements 114 may extend to each side part of the layeredpavement of the landside to replace the upper layer 102 and top-coat103.

The first and second gravel easements 114, may be further artificiallycooled by formation of a thin water film 115. The thin water film 115may be maintained during times of high insolation through a timed spraysystem 116, as shown in FIG. 4. The thin water film 115 can provideevaporative cooling to the gravel easement 114, which has a porous likestructure.

As illustrated in FIG. 5, the white concrete pavement 161 of the airsideof the airport area 1 or thermals-free zone 1 is actively cooled bymeans of a plurality of water pipes 162 that are embedded in the whiteconcrete pavement 161. The plurality of water pipes 162 may be made ofPVC or any other durable plastic material. Cooling water may becirculated through the plurality of water pipes 162 with the aid of apumping station 163 to maintain water temperature and flow sufficient toprovide a thermal equilibrium between the surface of the white concretepavement 161 and ambient air. The benefit gained from this arrangementis that the plurality of water pipes 162 may be utilized fortransporting warm water during winter season in cold regions to preventthe surface of the white concrete pavement 161 from freezing.

The layout and construction of the bird sanctuary zone 5 may enhance theformation of thermals to attract soaring birds, which sense the presenceof thermals through the emitted infrared and infrasonic waves, as wellas the associated humidity. The bird protected areas or bird sanctuaryzone 5 may be constructed according to the disclosure of either U.S.Pat. No. 2,268,320 to Brandt or U.S. Pat. No. 2,371,629 to Lee or any ofone of similar designs.

An exemplary bird sanctuary zone 5, according to the features of theinvention, is shown in FIG. 6. One side of the bird sanctuary zone 5 mayinclude a water body zone 6 and a top layer 201 of the exclusion zone 2.The bird sanctuary zone 5 may include a dark-colored or black body 51and a reflecting light colored or white surface 52, which rests on theearth surface 7 and extends underneath the dark-colored or black body51. The dark-colored or black body 51 is formed from a porous heatabsorptive material such as peat moss. The light colored or whitesurface 52 may be formed from sandy soil topped with oyster shells orsimilar heat reflective material of albedo significantly higher thanthat of the dark-colored or black body 51.

Through solar heating, the dark-colored or black body 51 absorbs heatand transfers the radiant heat to sensible heat, which, in turn, heatsthe air in contact with it by conduction means. At the same time, thelight colored or white surface 52 reflect the solar radiant heat causingthe temperature of the air in contact with the dark-colored or blackbody 51 to be raised, expanded and then risen to form a steadyup-draught of air, as shown in FIG. 6.

Similarly, the green area zone 4 can be constructed from natural grassand shrubs to provide a habitat for birds where they can nest, feed andbreed. Furthered by natural grass, birds and other animals, includinggulls, waterfowl, raptors such as hawks and other species flock toairfields to eat, drink and reproduce. By doing so, they pose apotentially dangerous safety problem for departing and arrivingaircrafts. Birds eat insects and grubs, which live in natural grass upto six inches (15 cm) below the soil surface. Birds also eat rodentsthat feed on the insects. Standing water, particularly after freshrains, attracts many species of birds, including waterfowl. Large birds,such as ducks or geese, also create dangerous conditions for aircrafts(classified herein as foreign object damage (FOD)). Natural grassfurther provides material and cover for birds to nest and breed.

FIG. 7 shows the construction of the green zone 4. On one side of thebird sanctuary zone 5 are the water body 6 and the top layer 201 of theexclusion zone 2. The green zone 4 includes a tall grass area 41, whichis in direct contact with the earth surface 7 and a reflecting lightcolored or white surface 42 that also rests on the earth surface 7. Thetall grass area 41 may include natural grass, shrubs and may alsocontain drainage water or narrow streams of water. The white surface 42may be formed from sandy soil topped with oyster shells or similar heatreflective material of albedo that is significantly higher than that ofthe tall grass area 41. This arrangement is conducive to the formationof up-draught particularly in the presence of cumulus clouds 8.

The invention disclosed herein may also be applied to militaryairfields, as well as civilian airports of any type or size.

In addition to attracting soaring birds (e.g., herring gull; great blueheron; ring-billed gull; Swainson's hawk; sharp-shinned hawk; laughinggull; Australian pelican; Franklin's gull; Caspian tern; commonblack-headed gull; other gulls, terns; hawks; eagles, kites (e.g.Mississippi kite and etc.)) to protected areas where thermals are likelyto be formed, other factors such as the availability of food, water,safe locations for nests and rest may also attract other birds besidethose mentioned above. Other birds may include the barn swallow/swallow;dark-eyed junco; mallard; American mourning dove; snow goose; hornedlark; common/great northern loon/diver; killdeer; rock dove/pigeon;perching birds; common Turkey; lesser scaup; common starling; easternmeadow lark; American robin; double-crested cormorant; American cliffswallow; American kestrel; lark bunting; northern pintail/pintail;gadwall; common buzzard/buzzard; western meadowlark; chimney swift;yellow-rumped warbler; common wood-pigeon; kittiwakes; Mexican/Do.-Str.stone-curlew/thick-knee; sparrows; buntings; and finches. All of thesebird species were responsible for the top 50 collisions with USAFaircrafts by First of January 2008. Hence, it is important to attractthem away from the paths of aircrafts during taking off or landing. Thisis in addition to denying them access to critical areas of airports andaircrafts and paths of taking off and landing aircrafts.

Although a limited number of exemplary embodiments of the claimedinventions have been described above, it is to be understood thatvariations and modifications will be apparent to those skilled in theart without departing from the scope and spirit of the inventions.Therefore, the scope of the inventions is to be determined solely by thefollowing claims and their equivalents.

What is claimed is:
 1. A method for denying soaring and migratory birdsaccess to critical areas of airports and airfields and paths of takingoff and landing aircrafts, comprising: eliminating a potential formationof thermals or up-draughts essential for lifting soaring and migratorybirds; and dividing critical areas of airports and airfields and pathsof taking off and landing aircrafts into a plurality of zones, whereinthe elimination of thermals or up-draughts leads to an avoidance ofconflict between taking off and landing aircrafts and the soaring andmigratory birds.
 2. The method of claim 1, wherein the plurality ofzones comprise: a thermals-free zone that includes an airside area and alandside area of the airports and airfields and the paths of taking offand landing aircrafts; an unrestricted zone of open and public spacesthat are not under the control of operators of the airports andairfields; an exclusion zone that separates the thermals-free zone fromthe unrestricted zone; a green area zone; a bird sanctuary zone; and awater body zone.
 3. The method of claim 2, wherein the pavement of theairside area of the thermals-free zone comprises: a high-albedo whitecement concrete; a white cement coating; and a first and a second graveleasements on each side of the pavement.
 4. The method of claim 2,wherein the pavement of the landside area of the thermals-free zonecomprises: an asphalt bottom layer; an upper layer and a top-coat layer.5. The method of claim 2, wherein the pavement of the landside area ofthe thermals-free zone further comprises first and second graveleasements that extend to a side part of the layered pavement of thelandside area to replace the upper layer and the top-coat layer.
 6. Themethod of claim 2, wherein the exposed surface of a structureconstructed on the thermals-free zone, comprises a roof and a siding,both of which are covered with a special coating material for reflectingsun rays.
 7. The method of claim 2, wherein the pavement of theexclusion area comprises: an asphalt bottom layer; and an off-white toplayer.
 8. The method of claim 3, wherein the first and the second graveleasements are artificially cooled by formation of a thin water film andmaintained by a timed spray system.
 9. The method of claim 3, whereinthe pavement of the airside of the thermals-free zone is actively cooledby a plurality of water pipes that are embedded in the high-albedo whitecement concrete.
 10. The method of claim 9, wherein the cooling waterfrom the plurality of water pipes is circulated through a cooling watertower with the aid of a pumping station.
 11. The method of claim 9,wherein the plurality of water pipes transport warm water during wintertimes to prevent freezing of the surface of the pavement of the airsideof the thermals-free zone.
 12. The method of claim 2, wherein the birdsanctuary zone comprises: a dark colored or black body and a lightcolored or white surface, which rests on the earth surface and extendsunder the dark colored or black body.
 13. The method of claim 12,wherein the light colored or white surface is formed from a heatreflective material of albedo that is significantly higher than that ofthe dark colored or black body.
 14. The method of claim 2, wherein thegreen zone comprises: a tall grass area and a reflecting light coloredor white surface, both of which rest on the earth surface.